Working on old MTD rototiller, (no model number can be found), but the briggs motor with it, does, (altho I can't find it at the briggs site, model 100902-0197-01).
Anyway reason for my post, I found a wire just hanging, coming from under the flywheel, and wanted to see if anyone had an idea of what it was, before I spend time pulling the flywheel off. I enclosed a pic below.
Thanks, Steve

 

Depending upon the year of the engine the wire leads to points.

There is a coil conversion to eliminate points if you have them.

 

That's an old engine and it originally used points for ignition. Looks like it had a newer coil put on with electronic ignition, eliminating the need for the points. The old wire is often left hanging as it is un-needed.